Outboard motors are powered by an engine which is positioned within a cowling of the motor. The engine includes an output shaft which extends downwardly therefrom and is arranged to drive a drive shaft. The drive shaft extends to a lower portion of the motor, where it is arranged to drive a water propulsion device of the motor, such as a propeller.
These motors include a lubricating system for providing lubricant to the engine. The lubricating system typically includes an oil pan and an oil pump for drawing oil from the pan and delivering through passages or galleries through the engine.
The oil pump is often driven off of a camshaft of the engine. A disadvantage of this arrangement is that the oil pump is driven at half the speed of the output shaft, and thus at a fairly low speed. In order for the pump to supply the necessary quantity of oil, the oil pump must then be much larger to compensate for its lower drive speed. The enlarge sized of the oil pump conflicts with the desire to keep the engine, and thus the cowling in which the engine is positioned, as small as possible.
An improved oil pump arrangement for an outboard motor of the type having an engine powering a water propulsion device, is desired.